Neurosciences for PLAB 1

A 68 year old man developed sudden right-sided weakness and slurred speech 90 minutes ago. His right arm is flaccid with power 1/5 and there is a right facial droop sparing the forehead. His blood pressure is 176/94 mmHg and capillary glucose 6.4 mmol/L. Non-contrast CT head shows no haemorrhage. What is the SINGLE most likely diagnosis?

1. Migraine with aura Positive visual phenomena spreading over minutes, followed by headache, in a younger patient with previous episodes. Onset 90 minutes ago with haemorrhage excluded is not that.
2. Stroke correct Correct. Sudden focal deficit with forehead SPARING, which localises the facial weakness to an upper motor neurone lesion and separates it from Bell palsy. The glucose has already excluded the mimic that matters.
3. Hypoglycaemia Can mimic stroke exactly and is instantly reversible, which is why glucose is checked in every suspected stroke. Onset 90 minutes ago with haemorrhage excluded makes it essential to exclude.
4. Space-occupying lesion Progressive deficit over weeks with headache worse in the morning and papilloedema. Onset 90 minutes ago with haemorrhage excluded is too sudden.
5. Todd paresis Transient weakness after a seizure, resolving over hours. Onset 90 minutes ago with haemorrhage excluded gives no seizure history.

The point: Immediate non-contrast CT head in everyone: the only question that matters first is whether it is a bleed. Thrombolysis within 4.5 hours if haemorrhage is excluded; thrombectomy up to 24 hours in selected large-vessel occlusion. If not thrombolysed, give aspirin 300 mg for 14 days. Do NOT lower blood pressure acutely in ischaemic stroke unless thrombolysing.

Source: NICE NG128 — Stroke and transient ischaemic attack in over 16s NICE · tier 1, national regulator or guidance

A 68 year old man developed sudden right-sided weakness and slurred speech 90 minutes ago. His right arm is flaccid with power 1/5 and there is a right facial droop sparing the forehead. His blood pressure is 176/94 mmHg and capillary glucose 6.4 mmol/L. Non-contrast CT head shows no haemorrhage. What is the SINGLE most appropriate initial investigation?

1. Capillary blood glucose Hypoglycaemia mimics stroke perfectly and is reversed in minutes. It is checked before anything else. Onset 90 minutes ago with haemorrhage excluded makes it the first bedside test.
2. Non-contrast CT head correct Correct. The only question in the first hour is bleed or no bleed, because that decides whether thrombolysis is possible. CT is fast, available and answers exactly that question; a normal scan early does not exclude infarction and is not meant to.
3. Electrocardiogram and prolonged cardiac monitoring Looks for atrial fibrillation as the source of embolism, which changes secondary prevention from antiplatelet to anticoagulant. Onset 90 minutes ago with haemorrhage excluded makes it important.
4. MRI brain with diffusion weighting More sensitive for early and posterior circulation infarction, but slower and less available acutely. Onset 90 minutes ago with haemorrhage excluded makes CT the practical first test.
5. Carotid Doppler ultrasound For anterior circulation stroke with a good recovery, to identify stenosis suitable for endarterectomy. Onset 90 minutes ago with haemorrhage excluded makes it part of secondary prevention.

The point: Immediate non-contrast CT head in everyone: the only question that matters first is whether it is a bleed. Thrombolysis within 4.5 hours if haemorrhage is excluded; thrombectomy up to 24 hours in selected large-vessel occlusion. If not thrombolysed, give aspirin 300 mg for 14 days. Do NOT lower blood pressure acutely in ischaemic stroke unless thrombolysing.

Source: NICE NG128 — Stroke and transient ischaemic attack in over 16s NICE · tier 1, national regulator or guidance

A 68 year old man developed sudden right-sided weakness and slurred speech 90 minutes ago. His right arm is flaccid with power 1/5 and there is a right facial droop sparing the forehead. His blood pressure is 176/94 mmHg and capillary glucose 6.4 mmol/L. Non-contrast CT head shows no haemorrhage. What is the SINGLE most appropriate immediate management?

1. Intravenous thrombolysis with alteplase correct Correct. Within 4.5 hours of a clearly witnessed onset, haemorrhage excluded, no contraindication. His blood pressure of 176/94 is below the 185/110 threshold and does NOT need lowering, lowering it in an untreated ischaemic stroke reduces perfusion to the salvageable penumbra.
2. Start anticoagulation immediately Deferred for up to two weeks after a large infarct because of haemorrhagic transformation risk, even in atrial fibrillation. Onset 90 minutes ago with haemorrhage excluded makes waiting correct.
3. Aspirin 300 mg for 14 days Started 24 hours after thrombolysis, once a repeat scan has excluded haemorrhagic transformation, then continued for two weeks before switching to long-term secondary prevention, and onset 90 minutes ago with haemorrhage excluded here points elsewhere.
4. Lower the blood pressure with intravenous labetalol Only when thrombolysing, or in haemorrhage. Lowering pressure in an untreated ischaemic stroke worsens penumbral perfusion. Onset 90 minutes ago with haemorrhage excluded makes it harmful here.
5. Mechanical thrombectomy For proven large-vessel occlusion, up to 24 hours in selected patients with salvageable tissue. Onset 90 minutes ago with haemorrhage excluded makes it appropriate.

The point: Immediate non-contrast CT head in everyone: the only question that matters first is whether it is a bleed. Thrombolysis within 4.5 hours if haemorrhage is excluded; thrombectomy up to 24 hours in selected large-vessel occlusion. If not thrombolysed, give aspirin 300 mg for 14 days. Do NOT lower blood pressure acutely in ischaemic stroke unless thrombolysing.

Source: NICE NG128 — Stroke and transient ischaemic attack in over 16s NICE · tier 1, national regulator or guidance